Anglo-Australian mining giant Rio Tinto said on Monday it had submitted feasibility studies to the Guinea government for its massive Simandou iron ore project, considered the world's biggest untapped iron ore deposit.

Simfer, Rio Tinto's subsidiary, "submitted today the bankable feasibility study (EFB) of the mine and the infrastructures of the Simandou South Project in Guinea", the world's No. 2 miner said in a statement.

"They are based on extensive analyses conducted during the last two years by Simfer, China Harbour Engineering Company (CHEC), China Railway Construction Corporation (CRCC) and other international mining and construction services providers."

The real cost of the project, which could have a major impact on Guinea's flagging economy, has yet to be revealed but it is tipped to reach $20 billion.